Lubricated non-woven fabric and method of producing the same

ABSTRACT

A NEEDLED NON-WOVEN FABRIC WHICH COMPRISES A NEEDLED WEB OF CRIMPED FIBERS OF A SYNTHETIC THERMOPLASTIC MATERIAL SUCH AS A POLYOLEFIN OR A POLYPROPYLENE. SAID WEB AND THE FIBERS THEREOF BEING LUBRICATED AND INCLUDING A SERIES OF LENGTHWISE EXTENDING, SPACED WARP THREADS OF A MATERIAL SUCH AS COTTON WHICH ARE RELATIVELY INEXTENSIBLE IN COMPARISON WITH THE NEEDLED WEB OF FIBERS. THE THERMOPLASTIC FIBERS COMPRISING THE NEEDLED WEB BEING BONDED OR FUSED INTO ENGAGEMENT WITH EACH OTHER ON ONE OR BOTH EXTERIOR SURFACES OF THE FABRIC. THE FIBERS ON ONE SUCH SURFACE ALSO BEING BONDED OR FUSED INTO ENGAGEMENT WITH THE WARP THREADS. THE REMAINING OR INTERIOR FIBERS OF THE FABRIC BEING UNFUSED AND MOBILE OR MOVABLE RELATIVE TO EACH OTHER. THE FIBERS OF THE NEEDLED FABRIC BEING LUBRICATED WITH A LUBRICANT SUCH AS COCONUT OIL TO INCREASE THE MOBILTIY OF THE UNFUSED FIBERS AND TO REDUCE THE NOISE RESULTING FROM TUFTING OF THE FABRIC. THE LUBRICANT ALSO PREVENTS OVERHEATING OF THE TUFTING NEEDLES. SAID NEEDLED AND LUBRICATED FABRIC IS PRODUCED IN A CONTINUOUS MANNER BY DEPOSITING FIBERS ON A CONTINOUSLY MOVING BAND OF SPACED WARP THREADS AND THEN NEEDLING THE LAYER OF DEPOSITED FIBERS AND THE WARP THREADS IN A VERTICAL DIRECTION RELATIVE TO THE THICKNESS OF THE FABRIC. THEN FUSING THE THERMOPLASTIC FIBERS ON AT LEAST ON EXTERIOR SURFACE OF THE WEB OF FIBERS INTO ENGAGEMENT WITH EACH OTHER AND WITH THE WARP THREADS WITHOUT FUSING THE REMAINING OR INTERIOR FIBERS OF THE WEB AND THEN APPLYING AN AQUEOUS SOLUTION CONTAINING A LUBRICANT TO AT LEAST ONE EXTERIOR SURFACE OF THE WEB.

D. B. PARLIN April 27, 1971 LUBRICATED NON-WOVEN FABRIC AND METHOD OFPRODUCING THE SAME Filed March 14, 1968 2 Sheets-Sheet 1 A ril 27, 1971o. B. PARLIN 3,576,637

LUBRICATED NON-WOVEN FABRIC AND METHOD OF PRODUCING THE SAME Filed March14, 1968 2 Sheets-Sheet 2 m N OR 34141) .Awmv

United States Patent 3,576,687 LUBRICATED NON-WOVEN FABRIC AND METHOD OFPRODUCING THE SAME David B. Parlin, Thompsonville, C0nn., assignor toBigelow-Sanford, Inc., New York, NY. Filed Mar. 14, 1968, Ser. No.713,186 Int. Cl. D04h 18/00 US. Cl. 156148 7 'Claims ABSTRACT OF THEDISCLOSURE A needled non-woven fabric which comprises a needled Web ofcrimped fibers of a synthetic thermoplastic material such as apolyolefin or a polypropylene. Said web and the fibers thereof beinglubricated and including a series of lengthwise extending, spaced warpthreads of a material such as cotton which are relatively inextensiblein comparison with the needled web of fibers.

The thermoplastic fibers comprising the needled Web being bonded orfused into engagement with each other on one or both exterior surfacesof the fabric. The fibers on one such surface also being bonded or fusedinto engagement with the warp threads. The remaining or interior fibersof the fabric being unfused and mobile or movable relative to eachother.

The fibers of the needled fabric being lubricated with a lubricant suchas coconut oil to increase the mobility of the unfused fibers and toreduce the noise resulting from tufting of the fabric. The lubricantalso prevents overheating of the tufting needles.

Said needled and lubricated fabric is produced in a continuous manner bydepositing fibers on a continuously moving band of spaced warp threadsand then needling the layer of deposited fibers and the warp threads ina vertical direction relative to the thickness of the fabric. Thenfusing the thermoplastic fibers on at least one exterior surface of theweb of fibers into engagement with each other and with the warp threadswithout fusing the remaining or interior fibers of the web and thenapplying an aqueous solution containing a lubricant to at least oneexterior surface of the web.

The present invention relates to a needled non-woven fabric and themethod of producing such a fabric. It relates more particularly, to alubricated non-woven fabric of the needled type which is suitable foruse as the backing fabric for tufted carpet or the like and to themethod of producing such a fabric.

An object of the present invention is to provide a needled-type ofnon-woven fabric comprised of thermoplastic fibers in which part of thefibers are mobile and carry a lubricant. This permits the mobile fibersto be deflected more readily by tufting needles and as a result, thereis little loss or change in the strength of the fabric when it istufted. This permits the tufting needles to be spaced more closely thanis usually the case.

The lubricant also reduces pounding and noise due to tufting operationsand it prevents the tufting needles from reaching a temperature wheredamage to the tufting yarns may result.

Another object of the present invention is to provide a non-woven fabricof the needled type in which =warp threads are incorporated in andextend lengthwise of the fabric adjacent one surface thereof. Such afabric can be produced at less expense than when woven threads areemployed.

An important feature of the present invention resides in the method bywhich the subject non-Woven fabric is produced on a continuous basis andwith a high degree of uniformity.

3,576,687 Patented Apr. 27, 1971 Generally speaking, a non-woven fabricof the type to which the present invention relates is described andclaimed in United States patent application Ser. No. 595,304 filed Nov.7, 1966, now US. Pat. No. 3,394,043, issued July 13, 1968 in the namesof David B. Parlin and Philip B. Mitchell and which is copendingherewith.

Briefly, a non-woven fabric embodying the present invention comprises aneedled sheet-like web of lubricated fibers of a high strength syntheticthermoplastic material including polyolefins, polypropylenes, polyestersand the like. The fibers are intermixed and entangled by the needlingwith portions thereof being displaced vertically relative to thethickness of the web. In addition to the fibers, warp threads of cottonor a similar material extend in spaced parallel relation to each otherin a lengthwise or 'warpwise direction of the web adjacent one surfacethereof.

The thermoplastic fibers on one or both exterior surfaces of the web arebonded or fused into engagement with each other with the fibers on thesurface adjacent the warp threads being fused or bonded to said threads.The remaining fibers of the fabric are not fused or bonded together andremain mobile relative to each other.

A lubricant applied to the web and the fibers thereof permits a largepercentage of the unfused or unbonded fibers to be deflected or pushedaside without being severed or broken in the passage of tufting needlesthrough the fabric. As a result, there is little change in the strengthof the fabric due to tufting.

More specifically, the needled web is formed from crimped fibers of ahigh strength synthetic thermoplastic material including polyolefins,particularly polypropylene in staple or fibrillated (split film) form.Fibers of other synthetic thermoplastic materials such as polyesters andmixtures may be employed. Where fibers of polypropylene are mixed withother fibers, the percentage of polypropylene fibers in the mixture ispreferably not less than 80%, but this will depend on the strengthrequirements. The fibers may be in the form of a 4 /2 in. staple and mayvary in size up to about 15 denier with different sizes being mixed. Forexample, a mixture containing six denier and 25% three denier fibers ofpolypropylene may be employed.

The warp threads may be of cotton, polyester, highmodulus rayon, nylon,polypropylene or the like. The material from which the warp threads aremade and the number of warp threads per inch will depend upon the costand strength requirements. In a non-woven fabric for use as the backingfabric for tufted carpet, 9/1 cotton or 18/1 polyester threads at aspacing of eight threads per inch have been found to providesatisfactory strength at low cost. In a four ounce fabric, this providesan elastic limit (tensile strength before permanent elongation) of about25 pounds per inch in the length or warpwise direction of the fabric.

In lubricating the fibers, an aqueous solution containing the lubricantmay be applied to one surface of the fabric after fusing. The lubricantsolution may be applied to the surface of the fabric by a padding orlick-roll. The amount of lubricant is about 4% by weight of the fabricand examples of solutions which have been found to be satisfactory, aresolutions containing 4% (by weight) of coconut oil; 3% (by weight) ofpeanut oil; 2% (by weight) of silicone; 2 /2 (by weight) of coconut oilwith /2 to 4% of a silicone and 2 /2% peanut oil with 4% of a silicone.Lubricants such as cottonseed, corn, linseed and tung oil may create afire hazard and hence, are not recommended.

As mentioned, the lubricant reduces the pounding and noise resultingfrom a tufting operation and prevents the tufting needles from reachinga temperature where damage to the tufting yarns, particularly duringstoppage of the tufting machine, may result. In addition, the lubricantresults in there being little loss in the textile strength of thenon-woven fabric after tufting. As explained, the lubricant permits themobile fibers to be more readily deflected or pushed aside by thetufting needles without being broken or severed. The fibers aredeposited by a cross-lapping operation by which a large number of thefibers extend in a widthwise direction relative to the fabric and whenthe fibers are not damaged or broken by the tufting needles, the tensilestrength in the width of the fabric can be maintained with acceptablelimits.

Under these conditions, it has been found that up to 12 stitches perinch and down to gauge may be employed in tufting without difficulty andwith little loss in the widthwise tensile strength of the backing fabriceven though the tufting needles may be in the neighborhood of .156" indiameter and hence, overlap at 12 stitches per inch. In the case ofnon-robbing or honesty type tubular needles, the subject non-wovenfabric will withstand up to 9 stitches per inch, whereas woven backingof jute and similar materials are generally restricted to around 7stitches per inch with such needles.

These and other features of the present invention will be better andmore clearly understood from the following description and theaccompanying drawings in which:

FIG. 1 is a perspective view diagrammatically illustrating a piece ofnon-woven fabric embodying the invention with certain portions thereofbeing broken away to illustrate details of its construction and beingdrawn to a somewhat enlarged scale;

-FIG. 2 is a section view taken along the line 22 of FIG. 1 and is drawnto a larger scale than FIG. 1;

FIG. 3 is a section view taken along line 33 of FIG. 1 and is also drawnto a larger scale than FIG. 1;

FIGS. 4 and 5 are section views corresponding respectively to FIGS. 2and 3, but showing the fibers and warp threads after needling and priorto fusing of the exterior surfaces thereof.

FIG. 6 is a diagrammatc plan view of machinery positioned to carry outthe invention; and

FIG. 7 is a side elevation of the machinery of FIG. '6.

It will be understood that the drawings are of a diagrammatic nature andreference should be made to the following description for a more detailexplanation of the construction of the subject fabric.

Referring now to the drawings, FIG. 1 shows a needled non-woven fabric10 formed from synthetic thermoplastic fibers of relatively highstrength such as polypropylene fibers or the equivalent thereof. Warpthreads 11 which are relatively inextensible as compared with theneedled web of fibers extend lengthwise of the fabric in spaced relationto each other and are incorporated in the fabric adjacent its lowersurface. The warp threads may be of cotton, polyester, or other materialhaving an elastic limit equal to cotton.

As will be described, the fibers are deposited by crosslappers whichoperate in a filling direction and the fibers are deposited in aflulfed-up condition on the warp threads as the warp threads advance.When the desired thickness of the fibers has been deposited on theadvancing warp threads, the fibers together with the warp threads aresubjected to the action of one or more needle looms in which barbedneedles are forced through the deposited fibers and to a point slightlybeyond the warp threads at closely spaced intervals. The barbed needleswhich are closely spaced, engage with the fibers and displace portionsof the fibers vertically with portions of some of the fibers beingdisplaced beyond the warp threads. This results in the warp threadsbeing located immediately above and adjacent the lower surface of theweb of fibers after needling.

The needling intermixes and entangles the fibers vertically relative tothe thickness of the fabric and compacts the fibers into a sheet-likeweb having substantial tensile strength, However, due to the nature of aneedled fabric and the properties of the fibers employed, the needledsheet-like web may be subject to undesirable elongation or stretching,particularly in its length. The warp threads which are made of cotton ora similar material, are less subject to such elongation or stretchingand thus, increase the elastic limit of the fabric in a lengthwisedirection.

The warp threads 11 extend lengthwise of the fabric in spaced parallelrelation to each other and in a non-woven backing fabric for tuftedcarpet, eight warp threads to the inch may be employed. It has beenfound that 9/1.

cotton or 18/ 1 polyester threads spaced at eight threads to the inchwill provide adequate strength for such a backing fabric and thisspacing avoids interference with or deflection of the tufting needles.The use of warp threads in this manner permits the non-woven fabric tobe produced in wide widths, such as nine and twelve feet, without theoverlapping required for woven materials such as cheesecloth due tolimitations as to the Widths in which woven materials are producedcommercially. Thus, the use of warp threads permits the non-woven fabricto be produced with greater uniformity and at less expense as weaving ofthe warp threads is not required.

As shown in the drawings, the thermoplastic fibers forming the lowersurface of the needled sheet-like web are fused, as indicated at 12,into engagement with each other and with the warp threads 11 which areadjacent such surface. The Warp threads are not sized or finished as inthe case of a woven material and hence, engagement of the fused fiberswith the warp threads can be more readily achieved. Such engagementprevents slippage of the warp threads relative to the fibers of thefabric and more effectively increases the tensile strength and elasticlimit of the fabric in its lengthwise direction.

The thermoplastic fibers forming the upper exterior surface of thefabric may also be bonded or fused into engagement with each other asindicated at 13, but the interior of remaining fibers of the needledsheet-like web remain in an unfused or unbonded condition and are mobileor free to move relative to each other.

A lubricant such as coconut oil carried on the fibers of the web permitsthe unbonded or unfused fibers to be more readily deflected or pushedaside without being damaged in penetration of the fabric by the tuftingneedle. A large percentage of the fibers lie in a filling or widthwisedirection of the warp threads due to cross-lapping and thus, there islittle change in the widthwise tensile strength of the fabric as theresult of tufting.

The lubricant also decreases the pounding or noise produced by thetufting operation and it prevent the tufting needles from becomingheated to a temperature Where tufting yarns, such as an acrylic yarn,may be damaged during stoppage of the tufting machine.

The procedure by which the subject non-woven fabric is produced will nowbe described. As will be seen from FIGS. 6 and 7, this is a continuousprocess and for the most part conventional equipment is employed. At theoutset, a band or series of spaced warp threads 11 are drawn from a beamor creel 20 by powered rolls 21 and are guided by suitable means such asa threaded roll in spaced relation to each other onto a slatted type ofcontinuous conveyor 22 having friction strips 23 on the surface of theslats to aid in maintaining the Warp threads in spaced relation and inadvancing the warp threads with the conveyor. The drive for the conveyor22 is connected to and synchronized with the power rolls 21.

As the warp threads 11 advance on the conveyor 22, fibers are depositedon the moving band or warp threads by a pair of cross-lappers 24 whichreciprocate back and forth across the width of the band of movingthreads. Each of the cross-lappers reciprocates at a speed whichdeposits four layers of the fibers on a given area of the moving warpthreads, with the fibers being laid generally in a filling directionrelative to the warp threads.

Each of the cross-lappers 24 is supplied with fibers from a garnet orcarding machine 25 and each of the garnets is in turn supplied withfibers from a secondary pair of cross-lappers 26 to which fibers aresupplied from another set of garnets 27. Feed boxes 28 supply fibers tothe second set of garnets. Fibers are delivered to the feed boxes fromthe usual blenders and pickers (not shown).

After the desired quantity of fibers has been deposited on the movingwarp threads, the fibers and the Warp threads which continue to moveenter a first needling loom 29 where the fibers and the warp threads aresubjected to the needling action of small barbed needles which arereciprocated vertically and are forced through the fibers to a pointbeyond the warp threads. In this operation, the barbed needles engagewith and displace portions of the fibers vertically, causing the layerof fibers to be compacted with fibers from different levels of the layerbeing intermixed and entangled. It also forces portions of some fibersbeyond the warp threads so that the warp threads are positioned in theneedled mass of fibers immediately above the lower surfaces thereof.

From the first needling loom, the needled fibers and the warp threadspass over a dancer roll into a second needle loom 31 where the needlingoperation is repeated. The dancer roll is counterbalanced so as to actas a takeup on the needled material as it passes from the first to thesecond needle loom and it compensates for differences in the speed atwhich the material being needled passes through the needle looms.

After the second needling, the needled web passes around a second dancerroll 32 and into a J-box 33. As the needled web is drawn from the J-box33, it passes around a third dancer or take-up roll 34 and is thenguided in a vertical path between a pair of heated rolls 35 by guiderolls 36 and 37. The heated rolls 35 exert some pressure on the needledweb and are maintained at a temperature which is sufficient to causethermoplastic fibers on exterior surfaces of the needled web to fusetogether during the time the web is in contact with the walls withoutfusing fibers on the interior of the Web. The thermoplastic fibers onthe lower surface of the Web are also fused into engagement with thewarp threads at this time.

The needled and fused web then passes around guide rolls 38, 39 and 40and is guided in a path which brings the lower surface of the web intocontact with the surface of a padding or lick roll 41 which is rotatablymounted in a receptacle 42 containing an aqueous solution of alubricant.

After the solution containing the lubricant is applied to the lowersurface of the moving web, the web is fed over a guide roll 43 intoanother J-box 44. As the lubricated web is withdrawn from the J-box 44,it passes over a series of guide rolls 45 and around a dancer roll 46from which it is guided by rolls 47 and 48 beneath slitting wheels 47which cut the web along its outer edges to the desired width.

The cut web then passes through an inspection area to a take-mechanism48 where the web is wound into rolls of the desired length.

It will be understood that various modifications and changes may be madein the embodiment of the invention which has been shown and describedherein without departing from the scope of the invention as defined bythe following claims.

What is claimed is:

1. A method of producing a needled non-woven fabric which comprises thesteps of depositing fibers at least some of which are of a thermoplasticmaterial, in a loose condition on a band of parallel, unconnected spacedwarp threads;

needling the deposited fibers and the warp threads in a verticaldirection at closely spaced points with barbed needles and therebycompacting the deposited fibers and incorporating the warp threads insaid compacted fibers adjacent one surface thereof; and

bonding the fibers on said one surface into engagement with each otherand with the warp threads by fusing said thermoplastic fibers with heatwithout bonding the fibers in 'the interior of the web.

2. The method of claim 1 comprising the step of applying an aqueoussolution containing a lubricant to at least one surface of the needledweb of fibers and warp threads.

3. The method of claim 2 wherein the aqueous solution contains from 2%to 4% by weight of a lubricant.

4. The method of claim 1 wherein the fibers are deposited generally in afilling direction relative to the warp threads.

5. The method of claim 1 wherein the fibers are deposited generally in afilling direction relative to the warp threads.

6. The method of claim 2 wherein the fibers are deposited generally in afilling direction relative to the Warp threads.

7. The method of claim 5 wherein the warp threads are continuouslyadvanced by powered rolls.

References Cited UNITED STATES PATENTS 2,568,144 9/1951 Cremer et a1.156148X 2,840,881 7/1958 Bateman 161-80 3,231,650 1/1966 Findlay et al.2873X 3,060,072 10/1962 Parlin et a1. 161-81X 2,978,785 4/1961 Wenzell2872.2X 3,296,063 1/1967 Chandler 2876X 3,383,273 5/1968 Pearson et a1.2872.2X 3,394,043 7/1968 Parlin et al. 161-154X 3,460,216 9/ 1969Campbell et al. 2875 CARL D. QUARFORTH, Primary Examiner G. G. SOLYST,Assistant Examiner U.S. Cl. XrR. 156-478, 306

